Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| mutagenicity of p-aminophenol in e. coli wp2uvra/pkm101 and its relevance to oxidative dna damage. | it was recently reported that p-aminophenol (p-ap) induces dna cleavage in mouse lymphoma cells, cho cells and human lymphoblastoid cells. the mutagenicity of p-ap has not, however, been detected by reverse mutation assays. the purpose of this study was to assess the mutagenicity of p-ap by reverse mutation assay using escherichia coli wp2uvra/pkm101, which has a spectrum for detecting mutations different from those of other strains in the family with an at base pair at the mutation site and has ... | 1998 | 9711270 |
| steam pasteurization of commercially slaughtered beef carcasses: evaluation of bacterial populations at five anatomical locations. | a steam pasteurization process (patent pending) has been shown to effectively reduce pathogenic bacterial populations on beef tissue and to significantly reduce naturally occurring bacterial populations on commercially slaughtered beef carcasses. the objective of this study was to determine the effectiveness of the steam pasteurization treatment for reducing bacterial populations at several anatomical locations on commerically slaughtered carcasses. before and after pasteurization treatment (82. ... | 1998 | 9709229 |
| an efficient sampling technique used to detect four foodborne pathogens on pork and beef carcasses in nine belgian abattoirs. | the method presented in this paper should prove useful in assessing the effectiveness of haccp plans developed in slaughterhouses. samples were collected by swabbing well-defined areas of pork and beef carcasses with sterile gauze. between 160 and 420 half-carcasses were swabbed in each of nine pork or beef slaughterhouses. swabs from five carcasses were placed in the same sterile stomacher bag, constituting a single composite sample. standard or validated analytical methods were used to isolate ... | 1998 | 9709223 |
| long-term effect of alkaline, organic acid, or hot water washes on the microbial profile of refrigerated beef contaminated with bacterial pathogens after washing. | the effect of 2% (vol/vol) lactic acid, 2% (vol/vol) acetic acid, 12% (wt/vol) trisodium phosphate, water at 72 degrees c and water at 32 degrees c washes on bacterial populations introduced onto beef carcass surfaces after treatment was determined for up to 21 days at 4 degrees c storage in vacuum packaging. beef carcass short plates were collected from cattle immediately after slaughter and subjected to the above treatments or left untreated (c). short plates were then inoculated with low leve ... | 1998 | 9708300 |
| thermal inactivation of escherichia coli o157:h7 isolated from ground beef and bovine feces, and suitability of media for enumeration. | rates of thermal inactivation of five strains of escherichia coli o157:h7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 cfu g-1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. for each strain and treatment temperature (54.4, 58.9, 62.8, 65. ... | 1998 | 9708297 |
| a representative microbial sampling method for large commercial containers of raw beef based on purge. | the purge from beef combos ( a boxed collection of beef trimmings) was tested as a means of representatively sampling the microbial content of this raw product. in the first experiment, purge was sampled from model beef combos that had been inoculated with bovine feces.. data from this experiment indicated a strong correlation (r = 0.94) between the total aerobic bacteria counts derived from the purge samples of a model beef combo and the total aerobic bacteria present in a rinse sample of the e ... | 1998 | 9708274 |
| use of hot water for beef carcass decontamination. | hot water treatment of beef carcass surfaces for reduction of escherichia coli o157:h7, salmonella typhimurium, and various indicator organisms was studied using a model carcass spray cabinet. paired hot carcass surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carcasses immediately after the slaughter and dressing process. all cuts were inoculated with bovine feces containing 10(6)/g each of rifampicin-resistant ... | 1998 | 9708247 |
| influence of escherichia coli endotoxin induced fever on the pharmacokinetics and dosage regimen of oxytetracycline in cross-bred calves. | the pharmacokinetics and dosage regimen of oxytetracycline were determined in healthy and febrile cross-bred calves following its single intravenous administration (10 mg kg-1). fever was induced by a single intravenous injection of e. coli endotoxin (1 microgram kg-1 i.v.). the elimination half-life (t1/2 beta) and the apparent volume of distribution [vd(area)] were slightly increased in febrile calves, as compared to healthy animals. the values of t1/2 beta and vd(area) were 3.22 +/- 0.20 h an ... | 1998 | 9704514 |
| actin enhances the haemolytic activity of escherichia coli. | actin is a major cytoskeletal protein of mammalian muscle and non-muscle cells. exposure of cells to soluble factors that damage cell membranes results in the release of actin into the extracellular spaces. the alpha-haemolysin (hlya) of escherichia coli is the prototype rtx (repeat in toxin) toxin and is thought to be important in virulence because of its ability to lyse cells by formation of pores in the cell membrane. these studies were conducted to determine if actin influences growth and ha ... | 1998 | 9695917 |
| expression and equilibrium denaturation of cardiac troponin i: stabilization of a folding intermediate during denaturation by urea. | human cardiac troponin i has been expressed at high level in escherichia coli as a fusion protein by using the expression vector ptac114. the expressed protein forms primarily intracellular inclusion bodies that are solubilized in the presence of 8 m urea. the purified troponin i is recognized by anti-(human cardiac troponin i) monoclonal antibodies. equilibrium denaturation of recombinant human troponin i and bovine troponin i is compared by monitoring changes in the protein's fluorescence and ... | 1998 | 9693083 |
| role of phe120 in the activity and structure of bovine pancreatic ribonuclease a. | phenylalanine120 is a candidate residue juxtaposing catalytic his12 and his119 in ribonuclease a (rnase a). to clarify its role in construction of the catalytic center, phe120 was replaced by alanine, tryptophan, leucine, or glutamic acid by site-directed mutagenesis. the transphosphorylation and hydrolysis activities of the mutant rnase as, respectively, toward cytidinyl 3',5' adenosine (cpa) and cytidine 2',3' cyclic monophosphate (c>p) were compared with those of the wild type enzyme. the km ... | 1998 | 9685734 |
| the region of alpha-lactalbumin recognized by groel. | the binding constants between disulfide-intact or various disulfide-reduced bovine alpha-lactalbumins and an escherichia coli chaperonin, groel, were determined by using the equilibrium dialysis method. the disulfide-intact and one-disulfide (cys6-cys120)-reduced alpha-lactalbumins were shown not to bind with groel both in the presence and absence of ca2+. the two-disulfide (cys6-cys120 and cys28-cys111)-reduced alpha-lactalbumin, which has the native-like tertiary structure in its beta-domain r ... | 1998 | 9685721 |
| enhancement by copper, zinc superoxide dismutase of dna damage and mutagenicity with hydrogen peroxide. | oxidative dna damage caused by hydrogen peroxide was enhanced by copper, zinc superoxide dismutase (cuznsod) in a concentration-dependent manner, as reflected by the formation of 8-hydroxy-2'-deoxyguanosine (8-oh-dg) and strand breaks. hydroxyl radical scavengers such as sodium azide, mannitol and 5,5-dimethyl-1-pyrroline n-oxide (dmpo), a metal chelator, diethylenetriamine-pentaacetic acid, and catalase decreased strand breaks and 8-oh-dg formation in dna. the deoxyribose assay showed that hydr ... | 1998 | 9679665 |
| association of herd management factors with colonization of dairy cattle by shiga toxin-positive escherichia coli o157. | management factors in 36 pacific northwest dairy herds were evaluated for their association with the prevalence of shiga toxin-positive escherichia coli o157 (e. coli o157) in dairy cattle. the within-herd prevalence of e. coli o157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. during the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husba ... | 1998 | 9678159 |
| differentiation and quantification of theileria sergenti piroplasm types using type-specific monoclonal antibodies. | antigenic properties of two representative allelic products of the major piroplasm surface protein (mpsp) of theileria sergenti were studied. sera from cattle infected with either of ikeda and chitose types of the parasite reacted strongly with homologous but weakly with heterologous recombinant antigens in immunoblotting. monoclonal antibodies (moabs) produced against the both allelic products of mpsp parasites reacted only to the immunizing antigen. these results suggested that crossreactivity ... | 1998 | 9673935 |
| virulence determinants of escherichia coli isolated from milk of sows with coliform mastitis. | escherichia coli isolates recovered from the milk of sows with coliform mastitis were examined to determine their biochemical and serologic characteristics, serum resistance and ability to adhere to fibronectin and bovine fetal fibroblasts. no common biotype was identified, and a variety of serovars were detected. ninety-five per cent of the investigated strains were serum resistant in swine serum. binding to fibronectin was demonstrated in most of the strains. at a binding level above 13% of th ... | 1998 | 9673580 |
| u1 snrnp inhibits pre-mrna polyadenylation through a direct interaction between u1 70k and poly(a) polymerase. | it has previously been shown in vivo that bovine papillomavirus represses its late gene expression via a 5' splice site sequence located upstream of the late polyadenylation signal. here, the mechanism of repression is determined by in vitro analysis. u1 snrnp binding to the 5' splice site results in inhibition of polyadenylation via a direct interaction with poly(a) polymerase (pap). although the inhibitory mechanism is similar to that used in u1a autoregulation, u1a within the u1 snrnp does no ... | 1998 | 9659922 |
| detection of verotoxin-producing escherichia coli o157:h7 by multiplex polymerase chain reaction. | we constructed primers for multiplex polymerase chain reaction (pcr) to detect verotoxin-producing escherichia coli (vtec) o157:h7. the multiplex pcr primers were designed from the sequence of the flagellin structural gene of escherichia coli flagellar type h7 (genbank under accession number l07388), and from the sequence of the rfbe gene of escherichia coli o157:h7 (genbank under accession number s83460). in addition to these primers, we used a primer pair reported by karch and meyer (j. clin. ... | 1998 | 9654369 |
| potent enzyme inhibitors derived from dromedary heavy-chain antibodies. | evidence is provided that dromedary heavy-chain antibodies, in vivo-matured in the absence of light chains, are a unique source of inhibitory antibodies. after immunization of a dromedary with bovine erythrocyte carbonic anhydrase and porcine pancreatic alpha-amylase, it was demonstrated that a considerable amount of heavy-chain antibodies, acting as true competitive inhibitors, circulate in the bloodstream. in contrast, the conventional antibodies apparently do not interact with the enzyme's ac ... | 1998 | 9649422 |
| endocytosis and mhc class ii expression by human oviductal epithelium according to stage of the menstrual cycle. | the epithelium is the first barrier against pathogens invading the lumen of the human oviduct. its expression of class ii major histocompatibility complex (mhc class ii) proteins suggests that it might play a role in antigen presentation during the local immune response. to study the role of the oviductal epithelium in antigen processing, its endocytic properties and mhc class ii expression were examined. for assay of endocytosis, fluorescein isothiocyanate-labelled bovine serum albumin (bsa-fit ... | 1998 | 9647540 |
| compensation of preliminary blood phagocyte immaturity in the newborn calf. | to estimate the functional maturity of the phagocytic defence in neonatal calves, we analyzed the characteristics of blood phagocytes from calves (n = 10) 1 h post partum (p.p.) and 4 h p.p. at 1 h p.p., all calves were colostrum-deprived, while 5 calves had received colostrum before the 4 h p.p. sampling. the results were compared to those obtained from 3-9-week-old calves (n = 10). phagocytic and oxidative burst activity of polymorphonuclear leukocytes (pmnl) and monocytes were determined in w ... | 1998 | 9646436 |
| factors affecting the heat resistance of escherichia coli o157:h7. | escherichia coli o157:h7 has been reported as being not particularly heat resistant. however, several factors which might increase its heat resistance have been investigated in this study using five strains. increase in growth temperature to 40 degrees c, as found in the cow gut, heat-shock at sub-lethal temperatures of 42, 45, 48 and 50 degrees c, and variable heating rate (1 degree c min-1 to 23 degrees c min-1) had no dramatic effect on heat resistance. growth phase had a marked impact on hea ... | 1998 | 9633099 |
| novel recombinant analogues of bovine placental lactogen. g133k and g133r provide a tool to understand the difference between the action of prolactin and growth hormone receptors. | two new analogues of bovine placental lactogen (bpl), bpl(g133k) and bpl(g133r), were expressed in escherichia coli, refolded, and purified to a native form. binding experiments, which are likely to represent the binding to site 1 only, to intact fdc-p1 cells transfected with rabbit (rb) growth hormone receptor (ghr) or with human (h) ghr, to nb2 rat lymphoma cells, or to rabbit mammary gland membranes prolactin receptor (prlr), revealed only small or no reduction in binding capacity. the comple ... | 1998 | 9632658 |
| adhesion of some probiotic and dairy lactobacillus strains to caco-2 cell cultures. | the adhesion of 12 different lactobacillus strains was studied using caco-2 cell line as an in vitro model for intestinal epithelium. some of the strains tested have been used as probiotics, and most of them are used in the dairy and food industry. human and bovine enterotoxigenic escherichia coli strains were used as positive and negative control, respectively. bacterial adhesion to caco-2 cell cultures was quantitated using radiolabelled bacteria. the adherence of bacteria was also observed mi ... | 1998 | 9631336 |
| research notes: prevalence of selected microbial pathogens in processed poultry waste used as dairy cattle feed. | processed poultry litter intended for dairy cattle feed was collected on 13 dairy ranches in the san joaquin valley of california and analyzed for the presence of significant bacterial pathogens associated with clinical disease in cattle or foodborne disease in humans. litter samples were collected from the surface and interior of the litter piles upon arrival on the dairies and 2 to 4 wk later. litter samples were cultured for salmonella, escherichia coli, campylobacter, and other bacteria. the ... | 1998 | 9628527 |
| association of genes encoding p fimbriae, cs31a antigen and east 1 toxin among cnf1-producing escherichia coli strains from cattle with septicemia and diarrhea. | fifty-six cnf1-producing escherichia coli strains isolated from cattle with diarrhea or septicemia were screened by pcr for the detection of pap, sfa, afa, clpg, or f17 adherence factor and east 1 toxin genes. all the isolates were pap-positive, in accordance with the close association of pap, cnf1 and alpha-hemolysin genes observed on human and porcine e. coli. only the gene encoding the p adhesin of class iii (prsg) was detected. genes encoding cs31a antigen (71%) and s fimbriae (34%) (but not ... | 1998 | 9627958 |
| the dinuclear center of cytochrome bo3 from escherichia coli. | for the study of the dinuclear center of heme-copper oxidases cytochrome bo3 from escherichia coli offers several advantages over the extensively characterized bovine cytochrome c oxidase. the availability of strains with enhanced levels of expression allows purification of the significant amounts of enzyme required for detailed spectroscopic studies. cytochrome bo3 is readily prepared as the fast form, with a homogeneous dinuclear center which gives rise to characteristic broad epr signals not ... | 1998 | 9623806 |
| the flavoprotein component of the escherichia coli sulfite reductase can act as a cytochrome p450c17 reductase. | the flavoprotein component (sir-fp) of the e. coli sulfite reductase was found to support 17 alpha-hydroxylation of pregnenolone in the presence of cytochrome p450c17. half maximum activity is obtained for a 1:1 ratio of sir-fp, expressed as monomer concentration, to p450c17. when compared to bovine nadph-cytochrome p450 reductase, sir-fp is about 12-15 times less efficient. p450c17 was demonstrated to interact specifically with the fmn-binding domain of the protein and the n-terminal part of si ... | 1998 | 9618257 |
| lipofection of cultured mouse muscle cells: a direct comparison of lipofectamine and dosper. | cationic lipid-dna complexes (lipoplexes) have been widely used as gene transfer vectors which avoid the adverse immunogenicity and potential for viraemia of viral vectors. with the long-term aim of gene transfer into skeletal muscle in vivo, we describe a direct in vitro comparison of two commercially available cationic lipid formulations, lipofectamine and dosper. optimisation of transfection was performed in the c2c12 mouse muscle cell line, before further studies in primary mouse myoblasts a ... | 1998 | 9614580 |
| mammalian mitochondrial methionyl-trna transformylase from bovine liver. purification, characterization, and gene structure. | the mammalian mitochondrial methionyl-trna transformylase (mtfmt) was partially purified 2,200-fold from bovine liver mitochondria using column chromatography. the polypeptide responsible for mtfmt activity was excised from a sodium dodecyl sulfate-polyacrylamide gel and the amino acid sequences of several peptides were determined. the cdna encoding bovine mtfmt was obtained and its nucleotide sequence was determined. the deduced amino acid sequence of the mature form of mtfmt consists of 357 am ... | 1998 | 9614118 |
| [acute diarrhea: stool water loss in hospitalized infants and its correlation with etiologic agents and lactose content in the diet]. | forty weaned male infants were studied during their first year of life, all hospitalized with acute diarrhea in the gastroenterology and metabolism unit of the hospital "umberto i", são paulo, sp, brazil. we evaluated and quantified water fecal losses, employing the metabolic bed technique, relating the feeding formula employed with the different causal enteropathogenic agents. 67.5% of the studied infants were under six months and 40% under three months of age. two groups were randomly assemble ... | 1997 | 9611297 |
| on-line dual microdialysis with esi-ms for direct analysis of complex biological samples and microorganism lysates. | a novel dual-microdialysis approach has been developed for fast and efficient fractionation and cleanup for esi-ms and esi ms/ms analyses of biological samples. a modified dynamic microdialyzer utilizing two mirror-image serpentine channels, which sandwich a regenerated cellulose membrane of selected molecular weight cutoff, serves as the first stage for the removal of high-molecular-weight components and cellular residue. the second stage employs a hollow microdialysis capillary to remove low-m ... | 1998 | 9599580 |
| the occurrence and replication of escherichia coli in cattle feeds. | sixty-three of 209 (30.1%) samples of cattle feed that were collected from multiple commercial sources and from farms were found to contain escherichia coli. however, none of the feed samples examined were culture-positive for e. coli o157. replication of fecal e. coli, including e. coli o157, was demonstrated in a variety of feeds at temperatures that were similar to those found on farms in summer months. fresh mixed rations containing corn silage were sampled from 16 dairies. rations from 12 o ... | 1998 | 9594399 |
| studies of the presence of verocytotoxic escherichia coli o157 in bovine faeces submitted for diagnostic purposes in england and wales and on beef carcases in abattoirs in the united kingdom. | a survey of beef carcases in abattoirs in the uk was carried out in order to estimate the prevalence of contamination with verocytotoxin-producing escherichia coli (vtec) serogroup o157. contamination with verocytotoxin-producing e. coli (vtec) o157 was confirmed in 0.47% of the 4067 (95% confidence limits 0.22-1.00%) of neck muscle samples. a significant tendency for carcases present in the same abattoir on the same day to have similar results was found, thus suggesting cross contamination. vte ... | 1998 | 9593489 |
| mitochondrial methionyl-trna transformylase from bovine liver. | substrate specificities of mammalian mitochondrial methionyl-trna transformylase (mtfmt) toward trna substrates were characterized in vitro. the mtfmt is able to formylate e. coli initiator methionyl-trna (met-trna(fmet)) as efficiently as mammalian mitochondrial methionyl-trna. furthermore, e. coli elongator methionyl-trna (met-trna(mmet)) also serves as a substrate for mt mtf, whereas e. coli mtf rigorously excludes e. coli met-trna(mmet) from formylation reaction. thus, mammal mt mtf is sugge ... | 1997 | 9586066 |
| endotoxin impairs agonist-induced calcium mobilization in bovine aortic myocytes by a nitric oxide-independent mechanism. | we hypothesized that endotoxin (lps) would impair vasoconstrictor-agonist-induced calcium (ca2+) mobilization by a nitric oxide (no)-dependent mechanism. we incubated bovine aortic myocytes (passages 16 to 23) for 22 to 24 hours with 0 to 1.0 mg/ml escherichia coli lipopolysaccharide (lps). medium (dulbecco's modified eagle's medium (dmem) + 10% fetal bovine serum (fbs)) was assayed for nitrite (chemiluminescence), and myocytes were loaded with fura-2 acetoxymethyl ester (fura-2am), after which ... | 1998 | 9579387 |
| expression of catalytically active human cytochrome p450scc in escherichia coli and mutagenesis of isoleucine-462. | cytochrome p450scc (p450scc) catalyzes the first step in steroid hormone synthesis, the conversion of cholesterol to pregnenolone. human p450scc has been poorly studied due to the difficulty of purifying reasonable quantities of enzyme from human tissue. to provide a more convenient source of the human enzyme and to enable structure-function studies to be done using site-directed mutagenesis, we expressed the mature form of human p450scc in escherichia coli. the expression system enabled us to p ... | 1998 | 9578606 |
| delta subunit of rat liver mitochondrial atp synthase: molecular description and novel insights into the nature of its association with the f1-moiety. | the f1 moiety of atp synthase complexes consists of five subunit types in the stoichiometric ratio alpha 3, beta 3, gamma, delta epsilon. of these, the delta subunit has received very little attention in the study of f1 preparations from eukaryotic cells. although recently shown to associate tightly with the beta subunit [pedersen, p. l., hullihen, j., bianchet, m., amzel, l. m., and lebowitz, m. s. (1995) j. biol. chem. 270, 1775-1784], the delta subunit is not resolved in the x-ray structure o ... | 1998 | 9578578 |
| effects of temperature and novobiocin on the expression of calf prochymosin gene and on plasmid copy number in recombinant escherichia coli. | escherichia coli strain hb101 harboring an expression plasmid bearing calf prochymosin gene under the control of the tac promoter was grown in the presence of iptg with or without novobiocin at 28 and 40 degrees c, respectively. the differential rates of synthesis of prochymosin inclusions, and, for comparison, of beta-lactamase and beta-galactosidase, as well as plasmid copy number, were determined during the first hours of steady state growth. at 28 degrees c the induced expression of prochymo ... | 1998 | 9569630 |
| cattle and verotoxigenic escherichia coli (vtec), an old relationship? | 1998 | 9569484 | |
| crystallization and preliminary x-ray analysis of a 1:1 complex between a designed monomeric interferon-gamma and its soluble receptor. | a variant of human interferon-gamma (ifn-gamma) has been created in which the two chains of the homodimeric cytokine were linked n- to c-terminus by an eight residue polypeptide linker. the sequence of this linker was derived from a loop in bira bifunctional protein, and was determined from a structural database search. this "single-chain" variant was used to create an ifn-gamma molecule that binds only a single copy of the alpha-chain receptor, rather than the 2 alpha-chain receptor: 1 ifn-gamm ... | 1998 | 9568913 |
| type specific and genotype cross reactive b epitopes of the l1 protein of hpv16 defined by a panel of monoclonal antibodies. | mouse monoclonal antibodies (mabs) were raised against the major capsid protein, l1, of human papillomavirus type 16 (hpv16), produced in escherichia coli with the expression plasmid ptrcl1. epitope specificity could be assigned to 11 of these 12 antibodies using a series of linear peptides and fusion proteins from hpv16. one mab (mc53) recognized a novel linear epitope that appears to be unique to the hpv16 genotype. a further 11 mabs were characterized as recognizing novel and previously defin ... | 1998 | 9568027 |
| combined effect of ampicillin, colistin and dexamethasone administered intramuscularly to dairy cows on the clinico-pathological course of e. coli-endotoxin mastitis. | the effects of a single intramuscular injection of a drug product containing ampicillin, colistin and dexamethasone, as a suspension in a diester of propylene glycol of medium-chain fatty acids, on the clinico-pathological course of experimental escherichia coli-endotoxin mastitis was examined in 30 dairy cows. cows were divided into five groups, six cows per group, and 24 of them were infused with e. coli endotoxin into two quarters of their udders. the drug product was injected at 25,000 iu co ... | 1998 | 9559523 |
| nadph-flavodoxin reductase and flavodoxin from escherichia coli: characteristics as a soluble microsomal p450 reductase. | in addition to their endogenous roles as an activation system for various escherichia coli metabolic pathways, the soluble flavoproteins flavodoxin (fld) and nadph-flavodoxin (ferredoxin) reductase (fpr) can serve as an electron-transfer system for microsomal cytochrome p450s. furthermore, since fld and fpr are structurally similar to the functional domains (fmn binding and nadph/fad binding domains, respectively) of nadph-cytochrome p450 reductases (p450 reductases), these bacterial proteins re ... | 1998 | 9558349 |
| phenotypic expression of k88 adhesion alone or simultaneously with k99 and/or f41 adhesins in the bovine enterotoxigenic escherichia coli strain b41. | f41-positive and f41-negative derivatives of bovine enterotoxigenic escherichia coli strain b41 carrying k88 or k88 and k99 plasmids were investigated for stability and expression of genes for their fimbrial antigens. either k88 plasmid alone or both k88 and k99 plasmids could be maintained in these strains though stability could depend on culture medium. k99 antigen could be detected in each strain bearing k99 plasmid. clones that produced k88 antigen or clones that did not produce this antigen ... | 1998 | 9556859 |
| a case-control study of verocytotoxigenic escherichia coli infection in cats with diarrhea. | the objectives of this study were to determine the prevalence of enteric verocytotoxigenic e. coli (vtec) infection in a population of cats in ontario, and to determine whether an association exists between the presence of vtec and feline diarrhea. fecal samples from 179 cats, representing 113 cats with diarrhea and 66 cats with normal feces, were cultured for e. coli. the fecal cultures were screened for verocytotoxin activity with a vero cell assay. confirmation of the presence of verocytotoxi ... | 1998 | 9553706 |
| isolation and characterization of verocytotoxin-producing escherichia coli o157 strains from dutch cattle and sheep. | in the periods from july to november 1995 and 1996, fecal samples from dutch cattle and sheep were collected at the main slaughterhouses of the netherlands, located at different geographic sites. the samples were examined for the presence of verocytotoxin (vt)-producing escherichia coli (vtec) of serogroup 0157. e. coli o157 strains could be isolated from 57 (10.6%) of 540 adult cattle, 2 (0.5%) of 397 veal calves, 2 (3.8%) of 52 ewes, and 2 (4.1%) of 49 lambs. immunomagnetic separation with o15 ... | 1998 | 9542902 |
| effects of growth hormone, insulin-like growth factor-i, and cortisol on periparturient antibody response profiles of dairy cattle. | the objectives of this study were to determine hormone and antibody response profiles from the prepartum period to peak lactation, and evaluate potential immunomodulatory effects of the classic endocrine hormones, growth hormone (gh), insulin-like growth factor-i (igf-i) and cortisol. specifically, 33 holstein cows were immunized with ovalbumin (ova) and escherichia coli j5 at weeks -8 and -3 prior to parturition. at parturition (week 0), cows received an additional immunization of ova. blood wa ... | 1997 | 9533267 |
| increased surface expression of cd11b receptors on polymorphonuclear leukocytes is not sufficient to sustain phagocytosis during escherichia coli mastitis in early postpartum dairy cows. | phagocytosis, cd11a and cd11b adhesion receptor expression, o2-production and maturity of circulating polymorphonuclear leukocytes (pmn) were studied during acute coliform mastitis in early postpartum dairy cows to obtain a better insight in the role of neutrophils in the pathology of this disease. the mammary gland of twelve newly calved high-yielding dairy cows was experimentally infected with escherichia coli. variability in clinical signs of mastitis and inhibition of milk production among c ... | 1997 | 9533266 |
| alteration in immune responsiveness during the peripartum period and its ramification on dairy cow and calf health. | substantial evidence indicates that innate and acquired defense mechanisms are lowest from 3 wk precalving to 3 wk postcalving. this lowered responsiveness includes aspects of systemic and mammary gland immunity that may account, at least in part, for the increased incidence of peripartum disease. the physical and metabolic stresses of pregnancy, calving, and lactation may contribute to this decrease in host resistance and the subsequent increase in disease incidence. however, variation among co ... | 1998 | 9532513 |
| risk factors for clinical mastitis in a random sample of dairy herds from the southern part of the netherlands. | the incidence of clinical mastitis in dairy cows was estimated in 171 randomly selected dairy herds from the southern part of the netherlands. a total of 1103 quarter cases was reported. the mean annual incidence rate was 12.7 quarter cases/yr per 100 cows. the modeling incidence rate of clinical mastitis at the herd level indicated that a number of risk factors were associated with a higher rate of clinical mastitis: one or more cows that were leaking milk, one or more cows with trampled teats, ... | 1998 | 9532495 |
| one-headed kinesin derivatives move by a nonprocessive, low-duty ratio mechanism unlike that of two-headed kinesin. | a single molecule of the "two-headed" motor enzyme kinesin can move along a microtubule continuously for many enzymatic turnovers (processive movement), and the velocity produced by one kinesin molecule is the same as that produced by many kinesin molecules (high duty ratio). we studied the microtubule movement driven at 1 mm atp by biotinated n-terminal fragments of drosophila kinesin heavy chain attached to streptavidin-coated coverslips at various surface densities. k448-bio has velocity at a ... | 1998 | 9521668 |
| evaluation of an enzyme-linked immunosorbent assay using recombinant major surface protein 5 for serological diagnosis of bovine anaplasmosis in venezuela. | an indirect enzyme-linked immunosorbent assay (elisa) was developed for the serological diagnosis of bovine anaplasmosis with purified recombinant major surface protein 5 (msp5) of anaplasma marginale produced in escherichia coli. serum antibody responses against msp5 were detected in calves experimentally infected with a. marginale as early as 21 days postinfection and reached maximum titers at 28 days postinfection. the msp5 elisa performed with serum samples taken from field cattle from diffe ... | 1998 | 9521155 |
| mechanisms of dna damage by chromium(v) carcinogens. | reactions of bis(2-ethyl-2-hydroxy-butanato)oxochromate(v) with puc19 dna, single-stranded calf thymus dna (ss-ctdna), a synthetic oligonucleotide, 5'-gatctatggacttacttcaaggccgggtaatgcta-3' (35mer), deoxyguanosine and guanine were carried out in bis-tris buffer at ph 7.0. the plasmid dna was only nicked, whereas the single-stranded dna suffered extensive damage due to oxidation of the ribose moiety. the primary oxidation product was characterized as 5-methylene-2-furanone. although all four base ... | 1998 | 9512527 |
| oligosaccharide-derivatized dendrimers: defined multivalent inhibitors of the adherence of the cholera toxin b subunit and the heat labile enterotoxin of e. coli to gm1. | poly(propylene imine) dendrimers having four or eight primary amino groups and a starburst (pamam) dendrimer having eight primary amino groups were used as core molecules, to which phenylisothiocyanate derivatized (pitc) galbeta1-3galnacbeta1-4[sialic acid alpha2-3]-galbeta1-4glc (oligo-gm1) residues were covalently attached to yield multivalent oligosaccharides. the synthesis of the oligo-gm1-pitc derivatized dendrimers was monitored using high performance thin layer chromatography, infrared sp ... | 1997 | 9511989 |
| reduction of carriage of enterohemorrhagic escherichia coli o157:h7 in cattle by inoculation with probiotic bacteria. | bacteria inhibitory to escherichia coli o157:h7 were isolated from cattle and evaluated for their potential for reducing carriage of e. coli o157:h7 in calves. eighteen of 1,200 bacterial isolates from cattle feces and intestinal tissue samples were screened and determined to inhibit the growth of e. coli o157:h7 in vitro. seventeen of the isolates were e. coli and one was proteus mirabilis. none produced shiga toxin. genomic dna fingerprinting by pulsed-field gel electrophoresis revealed 13 dis ... | 1998 | 9508288 |
| risks and prevention of contamination of dairy products. | consumers and regulatory officials are becoming increasingly aware of the human health risk of the presence of micro-organisms or chemicals in the agricultural environment. providing 'on-farm food safety' programmes which address the daily management of the production unit with regard to animal health and well-being, public health and environmental health must be a top priority for agriculturalists and veterinarians. developing critical control point management (ccpm) procedures for animal and h ... | 1997 | 9501360 |
| meat from dairy cows: possible microbiological hazards and risks. | the authors provide an overview of the circumstances associated with culling of dairy cattle in the united states of america (usa) and focus on the possible significant microbiological hazards associated with meat from cull dairy cows. cull dairy cows are an important source of food in the usa, accounting for at least approximately 17% of ground beef. the potential microbiological hazards for foodborne illness from cull dairy cows discussed here include salmonella (with special attention to s. t ... | 1997 | 9501354 |
| escherichia coli o157:h7 in livestock in japan. | the largest ever outbreak in japan of escherichia coli o157 infection in humans occurred in 1996. as a result, surveys were conducted later the same year to evaluate the sources and pathogenesis of this bacillus in livestock animals at the farm and in abattoirs. one of the surveys resulted in the isolation of e. coli o157 in 0.62% of cattle on randomly selected farms. although no confirmation has been made with regard to the source of e. coli o157 infection and its pathogenicity in livestock ani ... | 1997 | 9501352 |
| infectious agents associated with diarrhoea of calves in the canton of tilarán, costa rica. | a case-control study of calves under 3 months of age was carried out by weekly visits to 15 farms in the canton of tilarán, costa rica. most farms were dedicated to beef or dual-purpose (dp) production. faecal samples were collected over a 6-month period from a total of 194 calves with clinical signs and from 186 animals without clinical signs of diarrhoea as assessed by a scoring system. the samples were investigated for the presence of viruses, bacteria and parasites. torovirus was detected fo ... | 1998 | 9500174 |
| isolation from an ant myrmecia gulosa of two inducible o-glycosylated proline-rich antibacterial peptides. | reported here is the isolation and characterization of two antibacterial peptides synthesized in an ant myrmecia gulosa in response to bacterial challenge. the peptides were purified by reversed-phase high performance liquid chromatography and characterized by peptide sequencing and mass spectrometry. both peptides were formed from 16 amino acids, were rich in proline ( approximately 30%), and had n-acetylgalactosamine o-linked to a conserved threonine. the activity of a synthetic non-glycosylat ... | 1998 | 9497332 |
| purification and characterization of the hnda subunit of nadp-reducing hydrogenase from desulfovibrio fructosovorans overproduced in escherichia coli. | based on the dna sequence of its structural genes, clustered in the hnd operon, the nadp-reducing hydrogenase of desulfovibrio fructosovorans is thought to be a heterotetrameric complex in which hnda and hndc constitute the nadp-reducing unit and hndd constitutes the hydrogenase unit, respectively. the weak representativity of the enzyme among cell proteins has prevented its purification. this paper discusses the purification and characterization of the hnda subunit of this unique tetrameric iro ... | 1998 | 9485416 |
| sequence and context dependence of ef-hand loop dynamics. an 15n relaxation study of a calcium-binding site mutant of calbindin d9k. | the influence of amino acid sequence and structural context on the backbone dynamics of ef-hand calcium-binding loops was investigated using 15n spin relaxation measurements on the calcium-free state of the calbindin d9k mutant (a14d+a15delta+p20delta+n21g+p43m), in which the n-terminal pseudo-ef-hand loop, characteristic of s100 proteins, was engineered so as to conform with the c-terminal consensus ef-hand loop. the results were compared to a previous study of the apo state of the wild-type-li ... | 1998 | 9485409 |
| intergenic suppression of the gammam23k uncoupling mutation in f0f1 atp synthase by betaglu-381 substitutions: the role of the beta380delseed386 segment in energy coupling. | we previously demonstrated that the escherichia coli f0f1-atp synthase mutation, gammam23k, caused increased energy of interaction between gamma- and beta-subunits which was correlated to inefficient coupling between catalysis and transport [al-shawi, ketchum and nakamoto (1997) j. biol. chem. 272, 2300-2306]. based on these results and the x-ray crystallographic structure of bovine f1-atpase [abrahams, leslie, lutter and walker (1994) nature (london) 370, 621-628] gammam23k is believed to form ... | 1998 | 9480879 |
| [current resistance status of escherichia coli strains from bovine mastitis milk samples]. | between december 1996 and march 1997, 95 e.coli strains were isolated from mastitis milk samples from 95 different animals. in 29.5% resistance could be observed against one or several of the examined antibiotics. however, cefoperazone, polymyxin b, colistin and gentamycin proved effective against the majority of these strains. between 0 and 23% of e.coli were resistant against the single tested antibiotics. as opposed to earlier investigations a smaller number of chloramphenicol-resistant strai ... | 1997 | 9480542 |
| efficacy of parenteral administration of three antimicrobial agents in treatment of clinical mastitis in lactating cows: 487 cases (1989-1995). | to evaluate the efficacy of parenteral administration of procaine penicillin g, spiramycin, or enrofloxacin in the treatment of clinical mastitis in lactating cows. | 1998 | 9470054 |
| cloning, sequencing and expression of a cdna encoding bovine pancreatic deoxyribonuclease i in escherichia coli: purification and characterization of the recombinant enzyme. | the bovine pancreatic (bp-) dnase i gene has been cloned from bp-cdna and expressed in e. coli. a polynucleotide sequence of 1295 base pairs was deduced from clones of the cdna. the sequence showed an open reading frame which can be translated as a 282-amino acid polypeptide, including a hydrophobic signal peptide and the polypeptide of bp-dnase i. an expression plasmid was constructed by inserting into the vector pet-15b, a cdna fragment coding for bp-dnase i ligated with a hexanucleotide codin ... | 1998 | 9469931 |
| detection of vtec using specific dna probes and complex typing of escherichia coli o157. | the incidence of e. coli causing hemorrhagic colitis (hc) or non-bloody enteritis in hungary was studied using slt-i and slt-ii gene-probes as well as vero-cell toxicity and verotox-f tests. out of 41 e. coli o157 strains isolated in hungary between 1987 and 1996 15 strains (o157:hnm 4, o157:h77 8, o157:hnt 3) derived from hemorrhagic colitis (hc). hybridization was observed with slt-i and/or slt-ii in 19 strains. verocytotoxin production of e. coli of 23 other serotypes was proven by hybridizat ... | 1997 | 9468730 |
| giving selenium supplements to dairy cows strengthens the inflammatory response to intramammary infection and induces a growth-suppressing effect on mastitis pathogens in whey. | supplementing the feed of selenium-deficient diary cows with selenium (se)-yeast or selenite at a level of 0.2 p.p.m. induced self-cure of subclinical mastitis; the prevalence of quarters harbouring subclinical mastitis (bacteriological criteria) decreased to about one half during the 8 week supplementation period. three phenomena became apparent to explain the beneficial effect of selenium on mastitis: 1. the recruitment of phagocytes to the infected milk compartment of the udder was improved d ... | 1997 | 9465776 |
| [optimization of the polymerase chain reaction (pcr) for detection and characterization of shigatoxin producing escherichia coli (stec) in food]. | the polymerase chain reaction (pcr) was improved to detect shigatoxin producing escherichia coli (stec) in milk. numbers of colony forming units (cfu) in test samples, concentrations and types of primers, amount of mgcl2, types of thermostable dna-polymerase, and cycling programs were modified up to obtain the cleanest electrophoretic pattern and the highest sensitivity. experimental conditions for further characterization of stec-isolates by means of pcr are given by summarizing data from liter ... | 1997 | 9451840 |
| a community outbreak of vero cytotoxin producing escherichia coli o157 infection linked to a small farm dairy. | a community outbreak of infection with vero cytotoxin producing escherichia coli o157 (vtec 0157) occurred in a small area of north west england in 1996. an outbreak control team was established to investigate the outbreak and implement control measures. nine people developed symptomatic infections with vtec o157, and a further three were found to be excreting the bacteria. all were infected with the same genotype of vtec o157. three children under 5 years of age and one adult were admitted to h ... | 1997 | 9447786 |
| cloning and expression of bovine corneal antigen cdna. | a cornea-associated antigen (co-ag) has been found to be the target for autoantibodies in patients with mooren's ulcer. the study goals were to isolate a full-length clone encoding co-ag from a bovine corneal cdna library and to express this clone in escherichia coli (e. coli). | 1997 | 9426958 |
| the 'assembly-promoting sequence region' of microtubule-associated protein 4 failed to promote microtubule assembly. | in order to study the function of the bovine map4 microtubule-binding domain (the assembly-promoting (ap) sequence region), a fragment corresponding to the ap sequence region was prepared using an escherichia coli expression system. when the fragment was mixed with purified tubulin at 37 degrees c, the fragment caused a time- and dose-dependent turbidity increase, and the fragment bound to tubulin. however, the products were cold-stable, and amorphous aggregates were observed by electron microsc ... | 1997 | 9414090 |
| [detection and occurrence of verotoxin-forming and/or shigatoxin producing escherichia coli (vtec and/or stec) in milk]. | raw milk contaminated with vtec was described as a source of human ehec infection. diagnosis of vtec from milk is complicated by the low number of vt-positive cells in the total bacterial count, the great variety of serovars with different combinations of virulence markers and the lack of characteristic biochemical properties for the cultural detection of all vtec. the graduated procedure presented and used for the examination of milk samples is based on vt detection in suitable enrichment cultu ... | 1997 | 9412452 |
| inhibitory effect on lps-induced tumor necrosis factor in calves treated with chlorpromazine or pentoxifylline. | the inhibitory effect of chlorpromazine (cpz), pentoxifylline (ptx) and dexamethasone (dex) was investigated in a model of endotoxin shock in holstein calves following an intravenous administration of esherichia coli endotoxin (lps). initial correlations with its effects on the levels of tumor necrosis factor (tnf), a pivotal mediator of endotoxin shock, and clinical signs were obtained. the pretreatment of cpz or dex significantly decreased the serum levels of tnf, and reduced endotoxic shock. ... | 1997 | 9409530 |
| concentrations of alpha-tocopherol after intramammary infusion of escherichia coli or lipopolysaccharide. | fifteen holstein cows were used in a trial involving intramammary challenge to determine the effects of acute clinical mastitis on the concentrations of alpha-tocopherol in milk and plasma and the concentrations of neutrophils in milk and blood. cows were assigned to one of three experimental groups challenged by intramammary infusion of lipopolysaccharide, escherichia coli, or sterile phosphate-buffered saline. all quarters infused with lipopolysaccharide or e. coli were diagnosed with clinical ... | 1997 | 9406075 |
| characterization of the pasteurella haemolytica transferrin receptor genes and the recombinant receptor proteins. | the tbpa and tbpb genes encoding the transferrin receptor proteins, tbpa and tbpb, from pasteurella haemolytica a1 were cloned, sequenced and expressed in escherichia coli. the genes were organized in a putative operon arrangement of tbpb- tbpa. the tbpb gene was preceded by putative promoter and regulatory sequences, and followed by a 96 base pair intergenic sequence in which no promoter regions were found, suggesting that the two genes are coordinately transcribed. the deduced amino acid seque ... | 1997 | 9405205 |
| localization of the heme binding region in soluble guanylate cyclase. | soluble guanylate cyclase (sgc) is a heterodimeric hemoprotein composed of alpha1 and beta1 subunits. sgc is activated by nitric oxide (no) and therefore plays a central role in no signal transduction. activation of sgc by no is believed to be mediated by the interaction between no and the heme of sgc. spectroscopic and kinetic studies have shown that the heme of sgc is in a unique environment. characterization of the heme environment is critical to the understanding of the mechanism of no activ ... | 1997 | 9398330 |
| a genomic polymorphism located downstream of the gcvp gene of escherichia coli that correlates with ecological niche. | current evolutionary theory proposes that niche-adapted microbial populations might evolve through selection for favoured genotypes followed by clonal expansion (maynard-smith, 1991). possible correlations between genomic variation and ecological niche in escherichia coli isolates derived from human and animal sources were investigated by randomly amplified polymorphic dna (rapd) analysis. a 1.6-kb polymorphic marker was identified which was present in 60% of isolates from human clinical specime ... | 1997 | 9394461 |
| bovine spongiform encephalopathy: is it an autoimmune disease due to bacteria showing molecular mimicry with brain antigens? | bovine spongiform encephalopathy (bse) could be an autoimmune disease produced following exposure of cattle to feedstuffs containing bacteria showing molecular mimicry between bacterial components and bovine tissue. analysis of molecular sequence databases (genbank and swissprot) shows that three bacteria (acinetobacter calcoaceticus,ruminococcus albus, and agrobacter tumefaciens) share sequences with the encephalitogenic peptide of bovine myelin, while three molecules in escherichia coli show m ... | 1997 | 9370514 |
| persistence of escherichia coli o157:h7 in dairy cattle and the dairy farm environment. | the persistence of escherichia coli o157:h7 in cattle and the farm environment was investigated on eight ontario dairy farms positive for e. coli o157:h7 in a longitudinal study commenced one year previously. faecal samples from cows, calves, humans, cats, rodents, wild birds, a composite fly sample and numerous composite and individual environmental samples were cultured and tested for verotoxin-producing e. coli (vtec). vtec isolates were serotyped and e. coli o157:h7 isolates were phage typed ... | 1997 | 9363025 |
| a 1-year study of escherichia coli o157 in cattle, sheep, pigs and poultry. | samples of rectal faeces were collected immediately after slaughter from 400 cattle each month for a 1-year period and from 1000 each of sheep, pigs and poultry over the same period. samples were examined for escherichia coli o157 by enrichment culture in buffered peptone water with vancomycin, cefixime and cefsulodin followed by immunomagnetic separation and culture of magnetic particles onto cefixime tellurite sorbitol macconkey agar. e. coli o157 was isolated from 752 (15.7%) of 4800 cattle, ... | 1997 | 9363024 |
| virulence factors of verocytotoxin-producing escherichia coli isolated from raw meats. | pcr for verocytotoxin-producing escherichia coli (vtec) was positive in 4.6% of 2,440 raw meat samples; only beef, sheep, and venison samples were positive. none of the isolated vtec strains belonged to serogroup o157. additional virulence factors were detected in only a minority of strains, suggesting that most of these meat vtec isolates are not pathogenic. | 1997 | 9361444 |
| responses of antibody titers to intramammary immunization with escherichia coli j5 bacterin. | the effect of an immunization schedule on responses of antibody titers was tested following vaccination with an escherichia coli j5 bacterin. eighteen cows were equally distributed among three immunization schedules: 1) subcutaneous injection at 14 d prior to the end of lactation, intramammary immunization at 7 d after drying off, and subcutaneous injection at 30 d into the dry period; 2) subcutaneous injections at drying off, at 30 d into the dry period, and within 12 h after calving; and 3) un ... | 1997 | 9361212 |
| application of recombinant bovine viral diarrhea virus proteins in the diagnosis of bovine viral diarrhea infection in cattle. | the national animal disease laboratory (nadl) vaccine strain of bovine viral diarrhea virus (bvdv) genes for gp48 and p80 were expressed in escherichia coli. the bvdv-nadl gene for gp62 was integrated into a baculovirus genome for expression in spodoptera frugiperda (sf-9) insect ovarian cells. the antigenicity of baculovirus expressed bvdv protein was detected by anti-bvdv specific antibodies in an enzyme-linked immunosorbent assay (elisa), indirect immunofluorescent assay (ifa) and radio-immun ... | 1997 | 9355247 |
| a stable alpha-helical domain at the n terminus of the rialpha subunits of camp-dependent protein kinase is a novel dimerization/docking motif. | the rialpha subunit of camp-dependent protein kinase is maintained as an asymmetric dimer by a dimerization motif at the n terminus. based on resistance to proteolysis and expression as a discrete domain in escherichia coli, this motif is defined as residues 12-61. this motif is chemically, kinetically, and thermally stable. the two endogenous interchain disulfide bonds between cys16 and cys37 in rialpha are extremely resistant to reduction even in 8 m urea, indicating that they are well shielde ... | 1997 | 9353302 |
| a structural requirement of zinc for the folding of recombinant link protein. | we have cloned and ligated a full-length bovine link protein (lp) in the pmal-c2 vector and overexpressed it in fusion with maltose-binding protein (mbp) in escherichia coli. we have demonstrated dose-dependent binding of mbp/lp to biotinylated hyaluronan in a dot blot assay. a greater percentage of the expressed fusion protein was soluble, monomeric, and undegraded when the growth temperature was lowered, the growth medium was supplemented with zinc, and metal chelators were omitted from the ly ... | 1997 | 9344458 |
| detection of stec and epidemiological investigations in surrounding of a hus patient. | after occurrence of a case of hus infection in a 2-year-old infant from a dairy farmer's family living near oldenburg, investigations were performed in the infant's surrounding in order to elucidate the route of infection. since hospitalization took place at a late stage, it was not possible to isolate ehec from the patient's stool samples. however, e. coli o157 antibody determinations in serum were positive. since stec of serogroup o157 were found in faeces from the 34 dairy cows of the farm, s ... | 1997 | 9342886 |
| n-terminal truncation mutagenesis of equinatoxin ii, a pore-forming protein from the sea anemone actinia equina. | the role of the n-terminal segment 1-33 of equinatoxin ii, a 20 kda pore-forming protein from the sea anemone actinia equina, was studied by n-truncation mutagenesis. a part of this segment was classified as being amphiphilic and membrane seeking. wild-type equinatoxin ii and its mutants lacking 5, 10 and 33 amino acid residues, respectively, were produced in escherichia coli using t7 rna polymerase-based expression vector. soluble recombinant proteins were isolated from bacterial lysates and as ... | 1997 | 9342140 |
| interaction of the dna topoisomerase ii catalytic inhibitor meso-2,3-bis(3,5-dioxopiperazine-1-yl)butane (icrf-193), a bisdioxopiperazine derivative, with the conserved region(s) of eukaryotic but not prokaryotic enzyme. | icrf-193 [meso-2,3-bis(3,5-dioxopiperazine-1-yl)butane], a bisdioxopiperazine compound, has been shown to be a catalytic inhibitor of dna topoisomerase ii by stabilizing the enzyme in the form of a closed "protein clamp," an intermediate form in the catalytic cycle (roca et al., proc natl acad sci usa 91: 1781-1785, 1994). in view of its usefulness as a probe in the functional analysis of the enzyme, we tried further to define the domain(s) of the enzyme interacting with the drug by examining it ... | 1997 | 9337070 |
| effects of 4-ipomeanol on bovine alveolar macrophage function. | the objective of this study was to determine whether 4-ipomeanol toxicosis in calves impairs alveolar macrophage functions important in pulmonary defense against infectious agents. male holstein calves were given either 4-ipomeanol (3 mg kg-1, i.v.) or vehicle (polyethylene glycol 400). alveolar macrophages were recovered by pulmonary lavage 3 days later, and their capacities to phagocytose and kill e. coli, migrate toward zymosan-activated immune bovine serum, and produce interferon and interle ... | 1997 | 9336881 |
| cholelithiasis and cholecystitis in a dairy cow. | a 9-year-old holstein cow was evaluated for colic and decreased milk production of 2 days' duration. preoperative serum biochemical results suggested hepatic damage and cholestasis. on the basis of persistent signs of abdominal pain that were nonresponsive to analgesics, exploratory laparotomy was performed. the cow was found to have choleliths. cholecystocentesis was performed, and samples were submitted for cytologic examination and bacterial culture. bacterial culture yielded escherichia coli ... | 1997 | 9333096 |
| a simple filtration technique to detect enterohemorrhagic escherichia coli o157:h7 and its toxins in beef by multiplex pcr. | primers, specific for a unique base substitution in uida of escherichia coli o157:h7, were coupled with oligonucleotides for the shiga-like toxin i (slt-i) and slt-ii genes in a multiplex pcr assay. a minimum of 10(2) cfu per pcr (10 microliters) was necessary to amplify e. coli o157:h7-specific bands by multiplex pcr. food particles as well as various unknown metabolic by-products of bacteria inhibited the pcr, but a simple two-step filtration procedure eliminated this inhibition. to reliably g ... | 1997 | 9327582 |
| characterization of a gdp dissociation inhibitory region of adp-ribosylation factor domain protein ard1. | adp-ribosylation factors (arfs) are approximately 20-kda guanine nucleotide-binding proteins initially identified by their ability to stimulate cholera toxin adp-ribosyltransferase activity and later recognized as critical components in intracellular vesicular transport and phospholipase d activation. arf domain protein 1 (ard1) is a member of the arf family that differs from other arfs by the presence of a 46-kda amino-terminal extension. we previously reported that this extension acts as a gtp ... | 1997 | 9312116 |
| mammalian protein rap46: an interaction partner and modulator of 70 kda heat shock proteins. | a ubiquitously expressed nuclear receptor-associating protein of approximately 46 kda (rap46) was identified recently. interaction experiments with in vitro-translated proteins and proteins contained in cell extracts revealed that a great variety of cellular regulators associate with rap46. however, in direct interaction tests by the far-western technique, only 70 kda proteins showed up and were identified as members of the 70 kda heat shock protein (hsp70) family. interaction is specific since ... | 1997 | 9312007 |
| biochemical evidence that saccharomyces cerevisiae ygr262c gene, required for normal growth, encodes a novel ser/thr-specific protein kinase. | saccharomyces cerevisiae ygr262c gene, whose disruption causes severely defective growth, encodes a putative protein kinase shorter than any other protein kinase biochemically characterized to date and lacking some of the conserved features of these enzymes. here we show that the product of the ygr262c gene, pid261, expressed in e. coli with a c-terminal (his)6 tag, is a bona fide ser/thr protein kinase as judged from its capability to autophosphorylate and to phosphorylate casein and osteoponti ... | 1997 | 9305753 |
| chinese hamster protein homologous to human putative protein kinase kiaa0204 is associated with nuclei, microtubules and centrosomes in cho-k1 cells. | monoclonal antibody raised against a preparation of loach fish sperm centrosomes was used for screening of cdna expressing library of chinese hamster cho-k1 cells. two positive clones appeared to encode 628 amino acid protein fragment that was 72% identical to human kiaa0204 protein, i.e. putative protein kinase. polyclonal antibodies raised against products of cdna expression in e. coli recognized 210-kda polypeptide in cho-k1 cells and immunostained nuclear speckles, centrosomes and microtubul ... | 1997 | 9305747 |
| purification and characterization of the protein kinase encoded by the ul13 gene of herpes simplex virus type 2. | the proteins encoded by the ul13 genes of herpes simplex virus types 1 (hsv-1) and 2 (hsv-2) have been predicted to be protein kinases. to identify the ul13 gene product, we have raised a rabbit polyclonal antiserum against a his.tag-hsv-1 ul13 fusion protein. the antibody specifically reacted with the 60-kda ul13 fusion protein expressed in escherichia coli and also recognized 56- to 57-kda late proteins in nuclear fractions of hsv-1- and hsv-2-infected cells. on the other hand, novel casein ki ... | 1997 | 9300039 |
| activation of endothelial cell phospholipase d by migrating neutrophils. | vascular endothelium plays a critical role in regulating the integrity of intercellular adhesive and junctional contacts in response to migrating neutrophils during the inflammatory process. biochemical responses induced in endothelial cells by adherent, migrating neutrophils are poorly understood. this study was undertaken to explore the possibility that endothelial cell phospholipase d (pld) is activated when neutrophils migrate through endothelial cell monolayers in response to chemotactic st ... | 1997 | 9291695 |
| molecular cloning of the complementary dna for an additional member of the family of aortic aneurysm antigenic proteins. | we have purified and partially sequenced a protein from the adventitia of the human aorta (aortic aneurysm antigenic protein 40 kda; aaap-40) that has homologies to bovine aortic microfibril-associated glycoprotein (magp-36). it is immunoreactive with immunoglobulin g (iggs) purified from the serum and aortic wall of patients with abdominal aortic aneurysms. aaap-40 and magp-36 have fibrinogen-like and vitronectin-like motifs. screening an expression library constructed from human aortic adventi ... | 1997 | 9279320 |